Apparatus for forming a lap of textile fiber

ABSTRACT

A lap forming apparatus in which loose fibers are directed through a chute to a rotating condenser screen or drum by engaging the mass of fibers between a pair of rotating feed rolls adjacent the terminal end of the chute and directing the mass of fibers from the feed rolls through a passageway which terminates in a fiber density control zone alongside of the condenser drum and through which a suction air flow is effected into the condenser drum. The fibers are advanced and compacted against the drum at a compacting zone downstream of the control zone, and the density of the mass of fibers being fed into the compacting zone is controlled by sensing variations in suction pressure as effected by variations in the density of the mass of fibers in the control zone relative to a desired predetermined density, and the rate of suction air flow through the condenser drum is compensatively varied in response to the sensed variations in the suction pressure so as to carry forward with the condenser drum a uniform amount of fibers from the control zone for forming a lap of substantially uniform density therefrom in the compacting zone.

United States Patent Rowe, III 1 Sept. 9, 1975 APPARATUS FOR FORMING A LAP OF TEXTILE FIBER [57] ABSTRACT [76] Inventor: Daniel G. Rowe, III, 4323 Water Oak Rd., Charlotte, NC. 2821 1 [22] Filed: Oct. 20, 1972 21 Appl. No.: 299,215

Primary ExaminerDorsey Newton Attorney, Agent, or Firm--Parrott, Bell, Seltzer, Park & Gibson A lap forming apparatus in which loose fibers are directed through a chute to a rotating condenser screen or drum by engaging the mass of fibers between a pair of rotating feed rolls adjacent the terminal end of the chute and directing the mass of fibers from the feed rolls through a passageway which terminates in a fiber density control zone alongside of the condenser drum and through which a suction air flow is effected into the condenser drum. The fibers are advanced and compacted against the drum at a compacting zone downstream of the control zone, and the density of the mass of fibers being fed into the compacting zone is controlled by sensing variations in suction pressure as effected by variations in the density of the mass of fibers in the control zone relative to a desired predetermined density, and the rate of suction air flow through the condenser drum is compensatively varied in response to the sensed variations in the suction pressure so as to carry forward with the condenser drum a uniform amount of fibers from the control zone for forming a lap of substantially uniform density therefrom in the compacting zone.

2 Claims, 4 Drawing Figures SUCTION Souece 5TOC1 50 u tecE:

APPARATUS FOR FORMING A LAP OF TEXTILE FIBER This invention relates to an improved method and apparatus for processing loose fibers to form a lap of substantially uniform density and weight per unit length thereof.

In the formation of a fibrous lap, it is well known that uniformity in the density of the lap is most effectively achieved by controlling the density of the fibers upstream of and immediately prior to the compacting of the fibers into a lap. Various mechanisms have been proposed heretofore for controlling lap density, but have had the drawback that corrections in lap density were made by measuring a section of the lap which was already formed and, in response thereto, rectifying the amount of fibers being fed so that a subsequent section of the lap might be compensatively heavier or lighter than the measured section. More recently, a lap density control mechanism has been proposed utilizing stuffing rolls for stuffing loose fibers into an enclosure from which the fibers were drawn to form the lap, and photoelectric means were provided for measuring the average density of the fibers in the enclosure, and the rate of rotation of the stuffing rolls was compensatively increased or decreased to control the amount of fibers stuffed into the enclosure so as to maintain a uniform fiber density before the lap was formed. However, the latter type of control mechanism requires that the fibers be thoroughly opened before being stuffed into the enclosure in order for the photoelectric means to properly reflect the average density of the fibers within the enclosure. Also, where photoelectric means are provided for measuring the average density of fibers, it is apparent that the average density of blends of different colors of fibers could not be measured effectively because of the variations in light absorption and reflectivity of different colors.

It is the primary object of this invention to control the density of a lap being produced by controlling the density before the lap is formed, regardless of whether all the fibers are of the same or different colors and without necessarily thoroughly opening the fibers before forming a lap therefrom.

It is another object of this invention to control the lap density by pneumatically sensing and rectifying variations in the fiber density before the lap is formed.

It is a more specific object of this invention to provide an improved method and apparatus for processing loose fibers to form a lap of substantially uniform density therefrom wherein a mass of loose fibers is moved through a chute and to a foraminate outer surface of a rotating condenser drum by engaging the mass of fibers between a pair of rotating feed rolls positioned adjacent the terminal end of the chute and directing the mass of fibers from the feed rolls through a converging passageway terminating in a fiber density control zone alongside of the condenser drum, and wherein the fibers are compacted and advanced against the foraminate surface of the drum at a compacting zone downstream of the control zone, with the density of the mass of fibers being fed into the compacting zone being controlled by directing a suction air flow through the con trol zone into the condenser drum to suck fibers from the control zone toward the condenser drum to be conveyed forwardly thereby into the compacting zone. Also, means are provided for sensing variations in suction pressure as effected by variations in the density of the mass of fibers in the control zone relative to a desired predetermined density, and the rate of suction air flow through the condenser drum is compensatively varied in response to the sensed variations in the suction pressure so that the rotating condenser drum carries forwardly therewith a uniform amount of fibers from the control zone for forming a lap of substantially uniform density therefrom in the compacting zone.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIG. 1 is a schematic plan view of a plurality of fiber processing textile machines equipped with the improved lap forming apparatus of the present invention;

FIG. 2 is an enlarged fragmentary elevation of a portion of one of the fiber processing machines shown in FIG. 1, as embodied in a carding machine, looking substantially along Line 22 in FIG. 1, and schematically illustrating a preferred embodiment of the corresponding lap forming apparatus with portions thereof in elevation and other portions thereof in cross-section;

FIG. 3 is an enlarged fragmentary view of the lower portion of the lap forming apparatus shown in FIG. 2; and

FIG. 4 is a schematic view illustrating driving connections between the lickerin feed roll of the carding ma chine of FIG. 2 and the condenser drum as well as adjacent rolls of the lap forming apparatus.

Referring more specifically to the drawings, in FIG. 1 the invention is shown in association with a plurality or row of fiber processing textile machines, each of which may be of any well known type to which a lap of textile fibers is to be fed, such as a carding machine, picker, blender, felting machine or needling machine. In this instance, the machines of FIGS. 1 and 2 are shown in the form of carding machines broadly designated at 10 and to each of which the lap produced by a corresponding lap forming apparatus of the present invention is fed through a driven feed roll 11 to be formed into a card web by the usual lickerin cylinder 12, a main cylinder 13, and a doffer cylinder 14 in the usual manner, after which each web is drawn into a can by a conventional coiler 15.

As shown in FIG. 1, fibers in loose form are distributed to the various carding machines 10 from a stock source 20 by a distributor conveyor 21 which may be in the form of the usual rake or pneumatic conveyor which functions in a well known manner to distribute a mass of loose fibers into a substantially upright chute 23 adjacent the rear portion of each carding machine 10. Each chute may be of conventional construction and includes opposing side walls 23a, 23b between which upper front and rear walls 23c, 23d are positioned. Lower vibrating walls 23e, 23f are substantially aligned with the upper front and rear walls 23c, 23d and form therewith a substantially vertical passageway or channel, through which the corresponding mass of loose fibers moves from the distributor conveyor 21. Lower chute walls 23c, 23d may be vibrated by conventional or any suitable means, not shown, to aid in gravitation of the fibers in chute 23.

As shown in FIGS. 2 and 3, the front and rear chute walls 23c, 23e and 23d, 23f are spaced inwardly from respective front and rear chute housing walls a, b, and the lower portion of front housing wall a has an arcuate wall member C integral therewith whose front surface is curved to conform substantially to the foraminate outer surface or wall 24a of a rotating condenser drum 24. The condenser 24 extends substantially throughout the width of the carding machine or, at least throughout the width of the lap to be formed, and the lower edge of the arcuate wall 0 substantially defines the rearward or upstream limit of a fiber control zone C,- which upstream or rearward limit is also defined by the forward edge of the upper wall a of a duct means 25. The lower wall of duct means 25 is indicated at 25b in FIG. 3, and opposite sides of duct means 25 are closed by the lower portions of the opposing side walls 23a, 23b of chute 23.

It should be noted that duct means 25 is arranged to direct fibers from the effective terminal or lower end of chute 23 to the foraminate outer surface 24a of rotating condenser drum 24, and the upper wall 25a of duct means 25 extends substantially tangentially upwardly and away from the outer surface of condenser drum 24. Also, the lower wall 25b is spaced from and extends at an angle with respect to upper wall 25a and, also, lower wall 25b extends a substantial distance forwardly of the front or forward edge of upper wall 25a so as to underlie a substantial portion of condenser drum 24 and thereby define the lower wall of the control zone C. Thus, it can be appreciated that the duct means 25 defines with the foraminate wall 24a of condenser drum 24 a fiber density control zone C which extends alongside the condenser drum. It also follows that duct means 25 forms a forwardly converging passageway terminating in the fiber control zone C. In order to move the mass of loose fibers through the chute 23 and to the foraminate outer surface 24a of rotating condenser drum 24, the mass of fibers is engaged between a pair of spaced rotating feed rolls 26, 27 positioned adjacent the terminal end of chute 23 and at the ingress end of duct means 25.

A speed variator or variable speed drive mechanism 30 is drivingly connected to feed rolls 26, 27 by suitable driving connections 31 between the output of the variable speed drive mechanism 30 and feed rolls 26, 27. The input of variable speed drive mechanism 30 may be driven by a suitable electric motor or other motive means 32. Conveniently, the speed variator 30 and motive means 32 may be mounted on the rear wall member b of the housing of chute 23, as shown in FIG. 2.

Located downstream of and adjacent to the control zone C is a lap forming and fiber compacting zone D which includes means for compacting against the con denser drum 24 those fibers carried forwardly with the rotating condenser drum 24. Such compacting means comprises a rear pressure roll 34, an arcuate pressure plate and a front pressure roll or bottom delivery roll 36 arranged in that order. The proximal surfaces of condenser drum 24 and pressure roll 34 are spaced from each other a distance somewhat less than the distance between the lower wall 25b of duct means 25 and the lower surface of condenser drum 24, and the bottom delivery roll 36 preferably is disposed somewhat closer to the lower surface of condenser drum 24 than the pressure roll 34. The arcuate pressure plate 35 pref erably extends between and substantially in tangential relation to the upper surfaces of the two rolls 34, 36 so that pressure plate 35 extends forwardly in a slightly converging relation to the lower surface of condenser drum 24. Thus, fibers carried forwardly from control zone C into and through compacting zone D are progressively compacted until they pass over the bottom delivery roll 36. An upper delivery roll or stripper roll 37, which engages and rotates at the same surface speed as the foraminate outer surface or wall of condenser drum 24, cooperates with bottom delivery roll 36 to strip the compacted lap L from condenser drum 24 and to direct the same down an inclined guide plate 40 to the feed roll 11 of the carding machine 10.

As heretofore stated, the lower edge of the arcuate wall member c of the housing of chute 23 substantially defines the rearward or upstream limit of control zone C insofar as the periphery of the foraminate outer surface or wall 24a of condenser drum 24 is concerned. Thus, the wall member 0 conforms substantially to the outer surface of the rearward portion of condenser drum 24. The lower portion of the front wall a of the housing of chute 23, at its junction with arcuate wall member c defines the rear wall of an expansion chamber 41 which encloses the upper portion of condenser drum 24 therewithin. The front wall 41a of expansion chamber 41 is provided with a suitable resilient seal 42 thereon to substantially prevent the flow of air inwardly between the wall 41a and the periphery of drum 24 adjacent the area at which the compacted lap L is stripped from condenser drum 24. Additionally, a stationary arcuate shield 43 is disposed within condenser drum 24 with its outer surface being shaped to conform substantially to the interior surface of the foraminate wall 24a of the condenser drum. The extent of the arcuate surface of the shield 43 is such as to prevent the inward flow of air into condenser drum between the compacting zone D and the lower edge of rear wall 41a of expansion chamber 41, thus further insuring that stripper rolls 36, 37 may strip the compacted lap L from the outer surface of wall 24a of condenser drum 24. In other respects, condenser drum 24 may be of a generally well-known type and accordingly, a more detailed illustration and description of condenser drum 24 is deemed unnecessary. As is usual, opposite ends of condenser drum 24 are closed by end walls 24b, only one of which is shown in FIGS. 2 and 3.

An air flow passage or branch duct 45 communicates with and may be considered as a portion of each expansion chamber 41. Each branch duct 45 extends upwardly and is connected to a common duct 46 leading to a suitable source of suction or fan 47 which may be common to all of the machines 10 shown in FIG. 1. It is to be understood, however, that each fiber processing machine 10 may be equipped with an individual suction means or fan, if desired. In any event, the suction means 47 effects a suction air flow generally forwardly along the duct means 25, through the control zone C and into condenser drum 24. Of course, it is apparent that the suction air stream flows upwardly through the upper portion of the condenser drum, through expansion chamber 41 and through the ducts 45, 46 to the suction means 47. The proximal edges of pressure plate 35 and lower wall 25b of duct means 25 may be spaced from roll 34 to permit air to flow into the exit portion of control zone C. Also, lower wall 25b of duct means 25 may be perforate or porous, if desired, to permit air to flow through wall 25b in its course to condenser drum 24 at the control zone C.

As indicated in FIG. 4, the conventionally driven feed roll 11 of the carding machine 10 is drivingly connected to condenser drum 24, lap forming pressure rolls 34, 36 and stripper roll 37 so that the peripheral surfaces of condenser drum 24 and rolls 34, 36, 37 move at substantially the same surface speed and at a constant rate. Accordingly, if the density of the fibers at the exit portion of control zone C is held constant, the amount of fibers advanced into compacting zone D by the rotating condenser drum 24 and pressure rolls 34, 36 will be constant and will result in the formation of a lap of substantially uniform density being stripped from the condenser drum 24 by stripper rolls 36, 37.

In order to maintain a substantially uniform fiber density in control zone C, means are provided for sensing variations in suction pressure as effected by variations in the density in the mass of fibers in control zone C, relative to a desired predetermined density, and the rate of the suction air flow and the rate of rotation of feed rolls 26, 27 are each compensatively varied in accordance with the sensed variations in suction pressure so that, in effect, a substantially constant suction pressure is maintained within the condenser drum on the air flow upstream side of the control and compacting zone C, D at all times during operation of the apparatus. Accordingly, as shown in the central portion of FIG. 2, each branch duct 45 is provided with a suitable manually adjustable suction pressure sensing device 50 of any suitable type which may be adjusted to sense variations in suction pressure either side of a predetermined optimum suction pressure within the respective branch duct 45. Since such pressure sensing devices are generally well known, a detailed description and illustration thereof is deemed unnecessary. By way of example, each pressure sensing device 50 may be of a type known as a series 3,000 Photohelic (registered trademark) switch/gauge as described in a Bulletin B-33 distributed by Dwyer Instruments, Inc., Post Office Box 373, Michigan City, Ind. 46360, U.S.A. A pressure sensing and transmitting tube 50a extends from sensing device 50 through one wall of condenser drum 24 and its open end terminates within condenser drum 24.

Each suction pressure sensing device 50 is electrically connected to a pair of servomotors 51, 52. The servomotor 51 is drivingly connected to a damper or air valve member 53 disposed within the main suction duct 46 and aligned with the respective branch duct 45 so as to open and close and thereby regulate the effective size of the opening at the upper end of the corresponding branch duct 45. The servomotor 52 is connected to a speed adjusting arm 54 of speed variator 30 to thereby vary the output speed of speed variator 30 and the feed rolls 26, 27 relative to the input speed of the variator 30 as effected by motive means 32.

From the foregoing description, it can be seen that I have provided an improved method and apparatus for processing loose fibers to form a lap of substantially uniform density and weight per unit length, and wherein a mass of loose fibers is moved through each respective chute 23 and to the foraminate outer surface or wall 24a of the rotating condenser drum 24 by engaging the mass of fibers between the pair of rotating feed rolls 26, 27 positioned adjacent the terminal end of the chute 23. Feed rolls 26, 27 feed the mass of fibers through a converging passageway defined by the duct means 25 and terminating in the fiber density control zone C defined between the forward portion of the lower wall 25b of duct means 25 and a portion of the foraminate wall 24a of condenser drum 24. It is seen further that the fibers are compacted and advanced against the rotating foraminate wall 24a of condenser drum 24 in the compacting zone D which is positioned adjacent to and is actually coextensive with and downstream of the control zone C, with the density of the mass of fibers being controlled in the control zone C by directing a suction air flow through the control zone and into the condenser drum to suck fibers from the control zone toward the condenser drum for being conveyed forwardly by the condenser drum into the compacting zone. At the same time, sensing means senses variations in the suction pressure as effected by variation in the mass of fibers in the control zone C relative to a desired predetermined density so that the rate of the suction air flow as well as the rate of rotation of the feed rolls 26, 27 are compensatively varied in response to the variations in the suction pressure sensed by the sensing device 50 and so that the rotating condenser drum 24 carries forwardly therewith a uniform amount of fibers from the control zone C and into the compacting zone D for forming a lap of uniform density in the compacting zone D.

It should be noted that, during operation of the improved lap forming apparatus, the duct means 25 serves as a reservoir for fibers being sucked from the control zone C against that portion of the forwardly moving foraminate wall 24a of condenser drum 24 passing through the control zone. Thus, if the suction pressure in the condenser drum increases above the desired predetermined suction pressure, this indicates that excessive fibers have been attracted to the drum 24. However, sensing device 50 and damper 53 then effect an immediate drop in velocity of the air flow to momentarily lower the suction pressure so that the excess fibers will no longer be held, by suction pressure, in the lap being formed. Conversely, if there is an undesirable pressure drop in condenser drum 24, as effected by insufficient fibers being attracted to the drum 24, sensing device 50 and damper 53 then effect an imme diate rise in velocity of the suction air flow to promptly attract a compensating amount of fibers to the drum 24, causing the suction pressure to return to the desired level when the proper corrective amount of fibers has been attracted toward the condenser drum 24 so as to achieve the desired density in the lap to be formed in the compacting zone D.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

1. Apparatus for forming a lap of textile fibers comprising a chute adapted to receive a mass of loose fibers therein, a rotary condenser drum having a substantially cylindrical foraminate wall, duct means for directing fibers from said chute to said condenser drum and defining with said foraminate wall a fiber density control zone alongside of said condenser drum, spaced rotary feed rolls adjacent the terminal end of said chute for feeding fibers from said chute into said duct means, suction means for effecting a suction air flow through said control zone and into said condenser drum, means adjacent and downstream of said control zone for compacting the fibers against said wall of said condenser drum to form a lap thereof, means for sensing variations in suction pressure as caused by variations in density of the fibers in the control zone relative to a prederesponsive to said sensing means sensing said variations in suction pressure for compensatively varying the rate of rotation of said feed rolls to aid in forming the lap of substantially uniform density.

2. Apparatus according to claim 1 wherein said means for driving said rolls includes a speed variator drivingly connected to said feed rolls. 

1. Apparatus for forming a lap of textile fibers comprising a chute adapted to receive a mass of loose fibers therein, a rotary condenser drum having a substantially cylindrical foraminate wall, duct means for directing fibers from said chute to said condenser drum and defining with said foraminate wall a fiber density control zone alongside of said condenser drum, spaced rotary feed rolls adjacent the terminal end of said chute for feeding fibers from said chute into said duct means, suction means for effecting a suction air flow through said control zone and into said condenser drum, means adjacent and downstream of said control zone for compacting the fibers against said wall of said condenser drum to form a lap thereof, means for sensing variations in suction pressure as caused by variations in density of the fibers in the control zone relative to a predetermined density, means responsive to said sensing means sensing said variations in suction pressure for compensatively varying the rate of the suction air flow through said control zone and said condenser drum so that said condenser drum will carry a substantially uniform amount of fibers therewith from said control zone to said compacting means to form a lap of substantially uniform density, means for driving said feed rolls, and means operatively connected to said driving means and responsive to said sensing means sensing said variations in suction pressure for compensatively varying the rate of rotation of said feed rolls to aid in forming the lap of substantially uniform density.
 2. Apparatus according to claim 1 wherein said means for driving said rolls includes a speed variator drivingly connected to said feed rolls. 